.357 mag AA#7

I am wanting to load some 125 grain winchester HP's for my bolt action .357 rifle. I want to use some of the AA#7 that I have on hand but I am getting confusing load data. My Speer book says 12.0g - 13.5g but Accurate's load data on there website says 10.9g- 12.1g both show same OAL. Does anyone use this powder have any recipes? Thanks for the help.. My Lyman book does not show AA#7 for this bullet weight.

I would start at 10.2gr of #7.
Accurate #7 is a bit fast, I would use a slower powder.
Rifle and pistol data is not the same for 357 mag. + you are using a bullet that you have no data for.
What primer does Speer use ?

SHR970

January 13, 2013, 05:58 PM

I've used the old AA data and the Speer data that you are referring to. The 13.5 gr. load is no slouch....however, when it was published the powder was being made in the Czech. Republic...before that it was from Israel. It is currently made in the US; I have a new keg of it and it has a distinctly different appearance from the previous stuff.

Because of that, I will be reworking my loads to be on the safe side. The latest AA data is quite a bit subdued from their previous editions, even those that came after the US made powders were on the market. If you elect to use the Speer data, start at the bottom to be safe.

#7 won't give quite the velocity of H110 / W296 but you don't lose all that much either...at least where the older powders were concerned. It also works great with 9mm.

The old stuff is small,round, and dark. The new stuff is shinier and semi flattened.

sghart3578

January 13, 2013, 08:32 PM

I don't know how much of a help this will be for you but I load Accurate #7 in my revolvers under a 158 gr JHP made by Zero. It gives an honest 1200 fps from my 4" S&W 586. I love this powder. I have tried 12.5 gr under a 125 gr JSP from Zero but didn't have my chronograph that day. Both loads were very clean, very accurate and little to no flame.